 // 创建单个图标
 echart() {
   const chartCtr = L.control({
     position: "bottomright"
   });
   chartCtr.onAdd = function () {
     const div = L.DomUtil.create("div", "info chart");
     div.id = "chartControl";
     return div;
   };
   chartCtr.addTo(sgisMapBase.getMap());

   const barChart = echarts.init(document.getElementById("chartControl"));
   const barOption = {
     title: {
       text: "ECharts 入门示例"
     },
     tooltip: {},
     xAxis: {
       data: ["衬衫", "羊毛衫", "雪纺衫", "裤子", "高跟鞋", "袜子"]
     },
     yAxis: {},
     series: [{
       name: "销量",
       type: "bar",
       data: [5, 20, 36, 10, 10, 20]
     }]
   };

   barChart.setOption(barOption);
 }
